Electrical switch apparatus

ABSTRACT

An electrical switch includes sets of contacts and countercontacts, one set being mounted on a movable carrier which is moved by a pneumatic cylinder and piston arrangement in one direction and by return springs in the other direction. The air inlet into the pressure chamber of the pneumatic arrangement is provided with a ball valve which allows only a slow flow of air into the working chamber during movement of the contacts towards engaging position but allows rapid movement to disengaging position.

United States Patent smn [ Mar. 14, 1972 [54] ELECTRICAL SWITCHAPPARATUS [72] Inventor: Kurt Stoll, Schanbacher Str. 48,Esslinger-Hegensberg, Germany [22] Filed: Nov.2, 1970 [2l] Appl. No.:88,957

[52] US. Cl ..200/82 R, 200/166 H [51] Int. Cl. "H0lh 35/38 [58] Fieldoi Search ..200/82 R, 83 R, 83 J, l66 H;

[56] References Cited UNITED STATES PATENTS 3,472,984 10/1969 Cusick..200/82RX 3,433,909 3/1969 Phlieger,Jr. ..200/82R McMorran et al..200/34 Mighton ..200/83 R X Primary Examiner-C. L. AlbrittonAttorney-Jennings Bailey, Jr.

[57] ABSTRACT An electrical switch includes sets of contacts andcountercontacts, one set being mounted on a movable carrier which ismoved by a pneumatic cylinder and piston arrangement in one directionand by return springs in the other direction. The air inlet into thepressure chamber of the pneumatic arrangement is provided with a ballvalve which allows only a slow flow of air into the working chamberduring movement of the contacts towards engaging position but allowsrapid movement to disengaging position.

8 Claims, 2 Drawing Figures PATENTEDMARMIHYZ 3 549 7 9 INVDVTOR.

V m7? I'M/L BY ELECTRICAL SWITCH APPARATUS.

BACKGROUND OF THE INVENTION Field of the Invention The invention relatesto an electricalswitch apparatus.

SUMMARY OF THE'INVENTION The purpose .of thepresent invention is tomake. a switch apparatus, particularlya switch'contactor, which beingsimple hydraulic work chamber, whose movable transmission member isfixed by an. intermediate memberto. a movably. guided carrier for thecontacts or the countercontactsand upon whose actuation the movement ofthe carrierv corresponding to the relative movement between contacts andcountercontacts is effected with the help of thepressure medium throughthe intermediate member.

The pneumatic or hydraulic work chambercan be a singleaction .ordouble-action cylinder, and a workpiston can, for example, be movablyguided to and fro in the work cylinder, or a diaphragm, or rolldiaphragm can be used as a transmission member.

The arrangement accordingto the invention,,which.is best suited forswitchingand controllingmotors, has the advantage that item be used evenin areas and situationswhere there is risk of explosion, as instead ofelectrical-or magnetic actuation, thedevice isoperated pneumatically orhydraulically, The lifeduration of thenew apparatusis considerably.larger than in known comparable arrangements, .as in the latter the.

actuating-magnetis destroyed, damaged or worm out after a.

number of switch-operations, and the, airgapbecomes correspondinglynarrower. In this waythelife duration can be increased-five to.lO-times, and the-device is correspondingly. more reliable. Further, thebounce of:the contactsinthenew device is considerably reduced. Finally,there isthe further-advantage that, contrary to -known devices,,ahigheractuating force can be employed; this force isconstant, leading'inthe final analysis to a reduction in switching delay. When the subjectmatter is designed as a so-called contactor with double interruptor,the-life durationis increased as aresult of the uniform distribution ofoxidation-on the pairs of contacts.

BRIEFDESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERREDEMBODIMENTS In FIG. 1 of the drawings contacts 1, 2 areprovidedon'carrier 3, designed. as a longitudinal rod-shapedmember-which, in the. embodiment shown in FIG. 1 of the drawings, hasthe form of a so-called contactorwith double interrupter, and car? riespairs of opposed contacts .1 and 2. Naturally, several pairsv of suchcontacts can be provided. With each pair. of contacts 1 and 2 there isin the present case associated a pair of counter contacts'4and 5 whichare combined in pairs, which are stationarily arranged in-the casing. Ontheside of carrier 3 facing the actuatingdevice, a supportplate or. rod.6:,-is,provided, on t whichengage return springs 7,' 8,;such ascompressionsprings, associated with thecarrier, the other ends ofsaid-springs being. supported ona part9 of the. casing,-

In order to. actuate thecontaets and- -,count.ercontacts,.that is 4 inorderto produce-.therelative movement :between -.the co.n-. tacts'andcountercontacts, which servesto applysaidcontacts.

and countercontacts to oneanother ori to, separate ,them, a

pneumatic or hydraulicwork..chamberlO isaprovided, according to theinvention-as an actuatingdevice, said-work chamber. 10 beingdesignedas a.singleacti on.or asa double-action chamber.- In .thecaseofthesingle-actionchamberyas in-Ythe embodiment :shown' in the drawings, the-introduction; of thepressuremedium-into.theworkvchamberthrough apipellis associated .with the movement for-applying the contacts andcountercontacts tooneanother, while, in orderto producethe.

opposite movement, oneormore; retum-springs is :orare. as-.

sociated'with" a transmissionmember l3rwithinthe work cylinder. Sucharetumspringmay for example-be arranged inside. the; cylinder, andv actdirectly. on the transmission member. Thesprings .7, 8 alreadymentioned; or onlytone suchv spring, may be used asareturn spring-,-Finally, return springs may be associated both'with the transmissionmember,and; with the-contactcarrier, that is..a -c ombination oftheabove;

embodiment :may. b.e provided. In .-the case of the double-ac.-

tion chamber, the return springs may be eliminated I or, if necessary,weaker springs may be=used.1 As the drawingv shows,

the work chambermaybe acylinderand have as atransmis:

sion member'apiston- 13 which-ismovable to and fro inside the-cylinder.In the single-action pneumatic cylinder shown in the. drawing, .14 isthe exhaust, However, othertypes of actuating devices may be used; Inall *cases the actuating-.deviceofthe. carrier isparallel to that of thetransmission memberof-the, workchamber, orthey coincide.- Thetransmission ,member is. rigidly-connected to themovably guided contactcarrier by the; rod .152.

Theactuating device, the contactsand .theycountercontacts arehoused:with their associatedjactuating =and transmissioncomponents, ,in :acasing shown-only. diagrammatically at 16.; the space taken up canbekept small."

In the embodimentshownin llfi: l;o f.the;dr,a r/rings,springsv 7 and.S-aredesigned ascompressionsprings; likewise, a spring.

acting on piston 13. might .be designedasta compression sprin Thespringsnof the embodimentsshown tend -1to .separate t the contacts.andcountercontacts, while the; pressure medium. tends to-dothe opposite,thatzis; totbring the-contacts andcountercontactstogetheri However, thesprings maypf course alternatively beused'as tension springs, which.tenditobringthe contacts and countercontacts together, whileinthiscasethe. pressuremedium has. the: purpose of: separatingv them,

When the springs are designed astension springs, the contacts. 1 and2tbeing arranged on the otherside ofthecountercontacts 3;and, 4,-relative to the view in the drawing, provision can be. made for the.springs to separate the contacts and countercontacts, and ,forthe-pressure medium to bringthemtogether.

By.interchanging the air feed-and evacuation pipes, finally,

other variantscan beformed. All these variantsare intended for specialexamplesof use. 7

In FIG. 2 of'the drawings a single-action pneumatic cylinder 20 isusedwithin which the-piston,2l.car rying a sealing ring ring 23' isvmovable to,.and fro according-toarrows22': The

pressure air is. introducedwithin the cylinder throughthe channels 24,25-.1Whenair is entering through ,these channels,

ball26 rests on its seat 28, but-there is not-produceda sealing effect,since the ball 2.6.does notperfectly adhere to its seat. represented-bythebush or-sleeve-28. Between-balllfizandits seat 28- there remains-aradially directedfreespace or interspace 29;through .which-pressure aircoming-fromchannel 25 passes through ,channel .2.7 into .the chamber30of. the singleactionspneumatic. cylinder in order to -move thepistonv.and' its piston rod;3l in downward directionaccording to-ar row 22a.

Thereby, the carrierr32which is connected with the head 33- of thepiston rod 31 by a projection 34 engaged into the groove 35 of the head33 is moved also downwards according to arrow 22a and thus the contactsand countercontacts are applied one against the other. The purpose ofthe ball 26 which is subjected to the action of the spring 36 is toreduce the cross section of the passage of pressure air from channel 25to channel 27 as much as possible, in the manner ofa throttle. By thismeans the contact carrier is prevented from moving with too great aspeed downwards in direction of the closed position of the contacts,whereby undesired vibrations of the contacts could arise. When thecontacts are to be opened, then pressure is relieved, for example, bymeans ofa valve not shown, connected with channel 24 and this latterchannel is connected with the atmosphere. Then, pressure spring movespiston rod 31 and piston 21 in upward direction according to arrow 22band the air contained in chamber 30 is expelled through channels 27, 25and 24, whereby ball 26 is lifted from its seat so that the air may passunhindered and with full speed through these channels.

Although my invention has been illustrated and described with referenceto the preferred embodiments thereof, I wish to have it understood thatit is in no way limited to the details of such embodiments, but iscapable of numerous modifications within the scope of the appendedclaims.

Having thus fully disclosed my invention, what I claim is:

1. An electrical switch apparatus comprising sets of contacts andcountercontacts which are connectable to electrical cables and whichcorrespond to one another, and an actuating device associated with thesecontacts and countercontacts for producing a relative movement betweenthe contacts and countercontacts in order to bring them together or toseparate them, the actuating device including a fluid pressure workchamber containing a pressure medium, a movably guided carrier for oneof the sets, said actuating device having a movable transmission memberconnected to said movably guided carrier on whose actuation the movementof the carrier corresponding to the relative movement between contactsand countercontacts is effected with the help of the pressure medium,wherein the fluid-pressure work chamber is provided with an air inlet,and a throttle in said air inlet for reducing the speed of the airentering the work chamber, and wherein the throttle comprises a ball anda spring acting on the ball and a seat associated with said ball, apassage with small cross section betweensaid ball and said seat whichpassage connects said inlet with said work chamber, whereby the pressureair issuing from said work chamber upon disengaging the said contactsfrom said countercontacts lifts said ball from its seat.

2. A switch apparatus according to claim I, wherein the fluid-pressurework chamber is a single-action cylinder.

3. A switch apparatus according to claim 2, wherein the introduction ofthe pressure medium into the work cylinder is associated with themovement for bringing together the contacts and countercontacts, andreturn spring means associated with the transmission member in order toproduce the opposite movement.

4. A switch apparatus according to claim 1, wherein the fluid-pressurework chamber is a double-action work cylinder.

5. A switch apparatus according to claim 1, wherein the contacts arearranged on the carrier whose direction of movement is parallel to thatof the transmission member of the work chamber while the countercontactsare fixed.

6. A switch apparatus according to claim 1 wherein said sets constitutea contactor with double interruptor.

7. A switch apparatus according to claim 3, wherein the carrier for themovable contacts is a longitudinal rod-shaped member, whose longitudinalmedial axis coincides with the direction of movement of the transmissionmember, and which carries pairs of opposed contacts and, on the sidefacing the piston, a support plate or rod, on which the return springmeans engages.

8. A switch apparatus according to claim 1, wherein a work piston isguided to move to and fro in a work cylinder constituting the workchamber, said piston constituting the movable transmission member.

1. An electrical switch apparatus comprising sets of contacts andcountercontacts which are connectable to electrical cables and whichcorrespond to one another, and an actuating device associated with thesecontacts and countercontacts for producing a relative movement betweenthe contacts and countercontacts in order to bring them together or toseparate them, the actuating device including a fluid pressure workchamber containing a pressure medium, a movably guided carrier for oneof the sets, said actuating device having a movable transmission memberconnected to said movably guided carrier on whose actuation the movementof the carrier corresponding to the relative movement between contactsand countercontacts is effected with the help of the pressure medium,wherein the fluid-pressure work chamber is provided with an air inlet,and a throttle in said air inlet for reducing the speed of the airentering the work chamber, and wherein the throttle comprises a ball anda spring acting on the ball and a seat associated with said ball, apassage with small cross section between said ball and said seat whichpassage connects said inlet with said work chamber, whereby the pressureair issuing from said work chamber upon disengaging the said contactsfrom said countercontacts lifts said ball from its seat.
 2. A switchapparatus according to claim 1, wherein the fluid-pressure work chamberis a single-action cylinder.
 3. A switch apparatus according to claim 2,wherein the introduction Of the pressure medium into the work cylinderis associated with the movement for bringing together the contacts andcountercontacts, and return spring means associated with thetransmission member in order to produce the opposite movement.
 4. Aswitch apparatus according to claim 1, wherein the fluid-pressure workchamber is a double-action work cylinder.
 5. A switch apparatusaccording to claim 1, wherein the contacts are arranged on the carrierwhose direction of movement is parallel to that of the transmissionmember of the work chamber while the countercontacts are fixed.
 6. Aswitch apparatus according to claim 1 wherein said sets constitute acontactor with double interruptor.
 7. A switch apparatus according toclaim 3, wherein the carrier for the movable contacts is a longitudinalrod-shaped member, whose longitudinal medial axis coincides with thedirection of movement of the transmission member, and which carriespairs of opposed contacts and, on the side facing the piston, a supportplate or rod, on which the return spring means engages.
 8. A switchapparatus according to claim 1, wherein a work piston is guided to moveto and fro in a work cylinder constituting the work chamber, said pistonconstituting the movable transmission member.